Abrading machine



A. BJORKLUND June 10, 1930.

ABRADING MACHINE Filed July 16, 1927 aggizmd 7 2 M W Patented June 10, 1930 ARVID BJORKL-UND, OF MINNEAPOLIS, MINNESOTA ABRADING MACHINE Application filed July 16, 1927.

My present invention relates to an improved abrading machine and more particularly to a sander for finishing certain kinds of work, such as patterns, that cannot be finished on the customary disk sander, and has for its object to provide such a machine that is self-contained, portable, extremely simple, with few parts to get out of order and that are very accessible, andhighly efliw cient in its action.

To the above end, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a perspective view of the invention;

Fig. 2 is a View partly in side elevation and partly in central vertical section with some parts broken away;

Fig. 3 is a fragmentary view with some parts sectioned on the line 3-3 of Fig. 2 with the table shown in a tilted position by means of broken lines;

Fig. 4 is a fragmentary detail view in sec- 30 tion taken on the line 44 of Fig. 2, on

an enlarged scale;

Fig. 5 is a detail View in section taken on the line 55 of Fig. 2, on an enlarged scale;

Fig. 6 is a view principally in section 35 taken on the line 66 of Fig. 2, on an enlarged scale; and Fig. 7 is a perspective view of the adapter.

The numeral 8 indicates a base removably supported on four legs 9 cast in pairs, and to which legs the base is rigidly secured by screws. The pairs of legs 9 are rigidly but detachably connected by a pair of transverse tie rods 10. Cast with the base 8, at the 45 center thereof, is a case 11 which extends both below and above said base. In the bottom of the case 11 is a drain hole normally closed by a screw plug 12. Formed with the case 11, at the top thereof, is an inturned .50 flange 13 having a rabbeted seat 14: on which Serial No. 206,317.

is removably mounted a cover 15 for said case.

Overlying the case 11 is a round table 16 having a flat smooth work-supporting surface and suitably reinforced by ribs formed with the under side thereof. On the under side of the table 16 is a pair of diametrically opposite hinge lugs 17 having open notch-like seats 18 which straddle a pair of axially aligned pivot pins 19 rigidly secured in bearing brackets 20 formed with the flange 13. These pivot pins 19 extend inward from the bearing brackets 20 and the lugs 17 snugly fit between said brackets and thus hold the table 16 against edgewise movement longitudinally of the pivot pins 19 but with freedom for tilting movement about the axes of said pins.

Screws 21, having threaded engagement with the lower ends of the bearing lugs 17, prevent the table 16 from being lifted from said pivot pins 19. To remove the table 16 from the pivot pins 19 it is only necessary to remove the screws 21. To releasably but rigidly hold the table 16 in a horizontal position or different tilted positions, the same is provided with a quadrant 22 having a circumferentially extended slot 23, the center of which is at the axes of the pivot pins 19.

A set screw 24 extends through the slot 23, H

has shouldered engagement with the quadrant 22 and screw-threaded engagement with one of the bearing brackets 20. To positively position and further hold the table 16 in a true horizontal position there is provided a pin 25 adapted to be inserted through aligned bores in depending car 26 on the quadrant 22 and in the case 11.

A short chain 27 secures the pin 25 to the respective bearing bracket 20 to prevent the same from being lost. Formed in the top of the table 16, at the center thereof, is a large round openin 28, and the table, at its opening 28, is rab beted to afford a seat 29 in which is removably supported a disklike adapter 30 having a relatively long slot 31 at its center that extends transversely of the projected axes of the pivot pins 19.

Integrally formed with the under side of the cover 15 is a pair f depending ways 32 that extend nearly to the bottom of the case 11. A crosshead 33 is mounted in the ways 32 for vertical reciprocatory movement and supports an upright shaft 34 for reciprocating movements therewith. The

shaft 34 is journaled in a removable bearing 1 38 mounted in a hub-like depending flange 39 I formed with the cover 15 and keyed thereto against rotation. The shaft 35 terminates below the table 16, has a'tool-holding socket 40 formed therein, and a grooved wheel 41 is keyed to said shaft above the bearing 38.

Rotary motion is imparted to the. shaft 34, from an electric motor 42, by a round belt 43 which runs over the grooved wheel 41 and a grooved wheel 44 on the armature shaft of said motor. The motor 42 is turned on its side with its armature shaft parallel with the shaft 34, and its base 45 is bolted to the verticalmember of an L- shaped bracket 46 supported on an extension 47 integrally formed with the base 8 and detachably secured thereto by a nut equipped bolt 48 which extends through a longitudinally extended slot. 49 in said bracket and a bore in the base extension 47. Obviously, by 'adjustingthe bracket 46 toward or from the case 11, the belt 43 may be placed under the proper tension. The electric motor 42 is provided with'a switch 50 which extends above thebase 8 and case 11 where it is out of the way and at the same time easy to operate. A guard 51 for the belt 43 and wheel 44 is detachably secured to the vertical member of the bracket 4 and extends to the table 16. r

Reciprocatory .movement is imparted to the crosshead 33 from the shaft 34 by a worm 52 formed with said shaftand meshes with a worn gear 53 journaled at 54 to said crosshead and has on one of its faces a crank pin 55 towhich the lower end of alink 56 is pivoted. The upper end of this link 56 is pivoted to a pair of ears 57 formed with the cover 15 on the under side thereof. 0bviously, under the rotation of the shaft'34 the crosshead 33 will be reciprocated at a much-reduced speed over that of the rota tion ofsaid shaft dueto the ratio between said worm 52 and worm gear 53.

V A spindle 58 is removably applied to the upper end of the shaft-34 and isaxially aligned therewith. On the lower end of thisspindle 58 is a reduced shank 59 that fits in the socket 40' and is held by a set screw '60 for rotation with said shaft. The

spindle 58 projects through the slot 31 in the adapter 30 and materially above the table 16. r

A piece of sand paper 00 is applied around the spindle 58 and its longitudinal edge portions are fitted into a longitudinally extended slot 61 formed in said spindle to hold the sand paper in position. A piece of work y is positioned on the table 16 to be sanded by the spindle. By tilting the table 16 the work 1/ can be positioned at any desired angle in respect to the axis of the spindle 58.

Withinthe case 11 is a body of oil a in which the crosshead 33 and parts carried thereby work. It will be noted that the level of oil is substantially at the upper end of the crosshead 33 when in its lowermost position so that said crosshead will pick up sufficient oil during its upward stroke to lubricate the ways 32 and the shaft 34 will keep its bearing 38 lubricated. Itwill also be noted that the trunnion 36, worm 52, worm gear 53 and the crank connection 55 with the link will run substantially all of the time in thebody of oil 2. There will be sufficient splash to keep the upper bearing for the link 56 lubricated. With the parts thus lubricated, the life thereof will be materially lengthened and the machine will operate with very little noise.

Obviously, by loosening the screw 60 the spindle 58 may be removed from the shaft 34, and as previously stated, by removing the screws 21 the table 16 may be lifted from the bearing brackets 20. After the table 16 is removed from the machine, the

cover 15 may be removed from the case andall of the parts carried thereby. V a

The cover 15 is rigidly but detachably secured. in its seat 14 by a plurality of screws. 7

What I claim is 1. In a machine of the kind described, the combination with a case, a removable cover for the case, an upright shaft journaled in the cover, means for driving the shaft, means carriedvby the cover within the case for reciprocating the shaft, a table overlying the case, and a tool holder applied to the shaft to partake of. its rotary andreciprocatory' movements and extending through an aperture in the table.

2. In a machine ofthe kind described, a case having a displaceable cover, said cover having ways extending into the case, a

crosshead 0n the ways, an upright shaft by for axial movement therewith, a relatively fixed bearing in which the shaft is journaled for endwise sliding movement under the reciprocatory movement of the cross-head, means for rotating the shaft, and means operated by the shaft and having a relatively fixed base of resistance for reciprocating the cross-head and shaft.

4. In a machine of the kind described, a reciprocatory cross-head, a rotatable shaft iournaled on the cross-head and held thereby for axial movement therewith, a relatively fixed bearing in which the shaft is journaled for endwise sliding movement under the reciprocatory movement of the cross-head, means for rotating the shaft, a crank on the cross-head, an anchored link attached to the crank, and means for operating the crank from the shaft at a point between its journal on the cross-head and the bearing for reciprocating the crosshead and shaft.

5. In a machine of the kind described, a

reciprocatory cross-head, a rotatable shaft journaled on the cross-head and held thereby for axial movement therewith, a relatively fixed bearing in which the shaft is journaled for endwise sliding movement under the reciprocatory movement of the cross-head, means for rotating the shaft, a worm on the shaft between its journal on the cross-head and the bearing on the support, a worm gear journaled on the crosshead and meshing with the worm, and an anchored link cranlcconnected to the worm ear. 6 6. The structure defined in claim 1 in which the case contains a body of oil in which the means reciprocated by the shaft works.

In testimony whereof I afiix my signature.

- ARVID BJORKLUND. 

